Green building? As in green paint or unseasoned wood? No, “green building” is the industry buzzword for environmentally friendly, responsible, sustainable building.
Some green building practices are a replacement for standard stick-frame construction, while others focus on the home’s size or building technique. Traditional stick-frame-looking houses can be built using cordwood; timber framing; logs; structural insulated panels (SIPS); strawbale; adobe; concrete and prefabricated (kit) packages. Some shelters that take on a totally different look and feel from traditional houses are tipis, yurts, cob, dome and earth-sheltered houses.
For all of human history, people have built their homes from the materials at hand: stone, logs and dirt. As transportation improved and there was a need and desire for “bigger and better,” building materials were transported up to thousands of miles to construct wonderfully innovative and grand homes. With fuel costs risisng and the awareness of the fragility and limitations of our environment to provide us with all that we desire, architects and contractors are beginning to see the wisdom in sustainable building techniques. For generations, pioneers, back-to-the-landers, do-it-yourselfers and just plain creative folk have built houses from recycled and local materials, houses on wheels, micro-houses (Thoreau), tree houses and many other creative and fanciful designs.
As the Earth’s resources are depleted, another aspect of green building that is becoming important is the use of more effective insulating materials, such as SIPS, concrete, low-emissivity glass and passive solar design, to cut down on the amount of energy needed to heat and cool our homes. In addition, the kind of materials used in home building is changing with the realization that products that we thought were safe to use, may not be — such as arsenic-treated wood. Arsenic leaches into the soil and accumulates there. New plastic/wood products that last longer than treated wood and do not put harmful chemicals into the environment are available at most home improvement stores.
Green Building Resources
Straw Bale Construction
Excerpted from A House of Straw by Carolyn Roberts, Mother Earth News April/May 2003
In the early 1990s, I saw a TV show about a family without exceptional building skills who were building their own house with low-cost, natural materials that harmonized with our planet’s ecosystem. My do-it-yourself genes jumped for joy. I became obsessed with the idea of building a house made of straw bales, an abundant by-product of grain production, and finished with earthen plasters made from clay, sand and chopped straw. It couldn't be all that hard to stack up some bales and cover them with mud, I figured. This would be the ultimate craft project, save money and give me a beautiful home at the same time.
I kept studying everything I could find about natural building. It all made sense: By placing large windows on the south side of a house, we could use the low winter sun for heating and lighten our dependence on gas or electricity. By building walls with straw bales, we would have an R-50 insulation from the summer heat — more insulation than most homes even have in their ceilings. Of course, we would have to insulate the ceiling, too.
An earthen floor and earthen plasters would provide thermal mass for the interior of the house. Just as rocks absorb the heat of the sun and then continue to emit that warmth after the sun sets, the earthen plasters would heat or cool with the interior of the house and then emit and help maintain that temperature.
I thought we could build one of these houses slowly, over the years, somewhere out in the country, beyond the realm of building inspections — someday. However, my husband didn’t really share my dream. We ultimately went our separate ways: I found myself suddenly divorced and without enough monthly income to pay all our bills plus a mortgage; the time was upon me to turn my dream into reality.
The fact that I had no building experience, only $25,000 in savings and very little free time didn't bother me — at first. After all, I had a stack of how-to books on my coffee table and I would have the help of my two sons, Andrzej (pronounced ‘Andre’) and J.J. They were 15 and 17 when we began the construction of our straw bale home in the Sonoran desert near Tucson.
I was pretty sure I had an extreme challenge ahead of me, but I didn’t realize I’d be leaving my former life behind. In building this house I found new muscles, new ways of thinking and, especially, new friends. What I really wanted from my house was a joyful, meaningful life — and I found one.
Straw-bale building experts Bill and Athena Steen, and an architect, Wayne Bingham, gave me a sketch and floor plan. They had been working on small, efficient house designs that consume fewer resources and cost less to build.
The interior of my house is about 1,000 square feet of enclosed living space. The boys share the loft, and my bedroom and the bathroom are below. The west side of the house has a U-shaped kitchen and dining area. The enclosed porch is a passive-solar sunroom on the south side of the house that I can open up to the house when I want the warmth, or close off in the summer.
Through this house design, I learned simplicity. In preparation for moving into a smaller house, the boys and I gave away our extra possessions, keeping only what we really used, from the pots and pans in the kitchen to the clothes in our closets. We haven’t missed a single thing we gave away.
Laying The Foundation
The foundation was a dusty, difficult process with days of labor laying out the footings, then building forms for the concrete. I also had to dig deep trenches and lay plumbing from the house to the septic tank. It was a time when reality came crashing into my dream, and fear and fatigue threatened to destroy the project. I might have given up, if that had been an option. I learned to toss out self-pity and my jealousy of people who were spending their weekends by the pool. I stayed focused on being grateful that I had a passion and was being given the opportunity to turn my dream into reality. I also learned to divide the huge project into small steps and not to let myself become overwhelmed by the work that lay ahead of me.
Straw Bale Walls
After days of toiling with dirt and concrete, a lovely moment arrived when golden bales of straw were piled by the foundation and 20 people showed up to help raise my walls. I’d found these volunteers through friends, from notices I’d put in health-food stores and an announcement I’d sent out on the straw bale listserv. With an experienced straw-bale builder, Matts Myhrman, as our leader, we divided into teams to handle each wall and corner of the house. Some people tied custom bales to fit against the window and door bucks, while others raked the loose straw into bags for later use in our earthen plasters. I was the host, answering questions, providing food and making sure everyone had the supplies they needed.
On this day, I discovered the deep joy of building by community. Many of the volunteers were complete strangers who have now become friends, and they all worked hard to make sure my walls were straight and strong. Now, I eagerly attend every wall raising I can. Work and play don’t have to be separate experiences.
Raising the Roof
After enduring a post-wall-raising depression, I faced the challenge of putting a very steep roof over the bale walls. The scary part began when we had to fasten large sheets of oriented-strand board (OSB) and metal roofing on top of the trusses. To get through this phase, I had to overcome my fear of heights. I could feel the freedom of working high in the blue sky, with the birds and the tops of the saguaro cactus at eye level.
After we moved into a construction trailer on the land, the boys caught my enthusiasm and volunteered more often. I also found a consultant to help me with the difficult jobs, answer questions and tell me how to survive all the building inspections. I finally had the help and support I needed.
Windows and Doors
Once the roof was on, the basic structure of the house was completed, but there were many, many hours of carpentry to go as I filled in the gable ends and installed windows and doors. This took patience and more learning, along with hard work while I was balanced on ladders and scaffolds. But this was the spiritual part of the construction for me, as I began to relax with the work and enjoy my craft in the open desert on the long summer evenings. I almost regretted enclosing the house, shutting out the soothing, melodic sounds of nature.
More Natural Materials
One year after the wall-raising party, I was ready to have another gathering to coat the bales with plasters made from clay and chopped straw. Sixteen people showed up on a cold, wet day and worked in teams, chopping straw, mixing mud and covering the entire house in one day. Again, I was so touched by the hard work that people, many of them strangers, put into my house. This house was built by a community of people who love natural building.
Installing the earthen floor was like running uphill at the end of a marathon. It truly was only with the help of a steady stream of volunteers that I made it through this difficult work.
When my house passed its final inspection, I felt as though I had graduated from college and put on a Broadway production at the same time. I was tired, but I was a stronger, more joyful person with a great faith that life is ours for the creating, as long as we don't give up on our dreams. I still enjoy making things more than buying them — even houses.
We’ve been in the house almost two years now. The fun really began after we moved in as I covered the earthen plasters with pottery clays and the drywall with burlap soaked in clay and water. We love the solid, slightly uneven walls with their natural textures, and I especially enjoy my low mortgage and utility bills. We truly have a home, sweet home.
Carolyn’s House of Straw
Excluding the porch expenses, and using the exterior dimensions of 1,200 square feet, construction costs were calculated at $37 per square foot. Using the interior living space of 995 square feet, calculated costs were $45 per square foot. The 925-square-foot covered porch cost $7,000, or $7.57 per square foot. Carolyn borrowed $50,000 from the bank and pays about $425 a month toward her mortgage.
Things I Learned About House Building
- Live in an old beat-up trailer while you build. This way your new home will feel like a mansion. If your trailer is too comfortable, you'll take longer to build the house.
- Read all the how-to books you can, even if you don’t remember what’s in them. You’ll get the gist of things and know why you have to do something in Phase 1 of the house to prepare for Phase 5. You can look up the details when you get to that part of the construction
- Help other people build their houses before you begin. Even if it isn’t the same kind of house, you'll learn a lot. It’s good karma, and they probably will show up to help you, too.
- Spend time outdoors in all kinds of weather in your area before you begin the house. Learn how to stay warm in the cold, cool in the heat and protect yourself from sun, rain and wind. You’ll be working in all these conditions.
- Be sure you have a good consultant who knows how to deal with your inspectors.
- Avoid anything that demands a time frame; it will take a whole lot longer than you think.
- Have a backup plan for more money; the house will cost more than you think.
- Have lots of pencils and at least two measuring tapes. Have a place for each tool and put it there when you are done, so it will be there when you need it again.
- For every problem, there is a solution. Don’t panic, just find the solution.
- Yeah, go ahead and read the directions on the stuff you buy, especially those bags of lime.
- Even though part of the beauty of straw bale houses is their handmade unevenness, build plumb and square. You’ll be glad you did when it comes time to add the roof, doors and windows.
- Build with joy and gratitude for this experience. When people are helping you, dance and sing. When you are alone, listen to the sounds of nature around you and feel the internal rhythm of your work.
- A house built with friends and family is more than a house; it’s a home. The difference is huge.
- If we never march intently toward our dreams, ignoring our fears and doubts, we will never know what might have been. (I think I said that, but it might be half-remembered Emerson.)
Excerpted from The Charm of Cordwood Construction by Rob Roy, Mother Earth News June/July 2003
This ancient building style — many references date it back 1,000 years — has known a substantial rebirth since the first articles about it appeared in Mother Earth News a quarter of a century ago. In cordwood construction, walls are constructed of log-ends — short logs, 12 to 24 inches long — mortared up transversely in the wall, similar to the way firewood is stacked.
In Canada, it’s commonly known as stackwall building. Log-ends can be cut from wood that is unsuitable for other purposes, such as fire-killed standing wood, ends and pieces from a sawmill, logging slash, and curved branches and trunks. Portland cement, mixed with sand, sawdust and builder’s lime, generally serves as the mortar between the “courses” of cordwood.
Why Build with Cordwood?
In 1974, Jaki and I bought land in northern New York to pursue our vision of a self-reliant lifestyle. In those days, the “natural building” structure of choice was the log cabin. We had helped with constructing a log home, and we knew from experience that fitting and hefting the large logs was a lot of hard work. We also knew that in our area, 15 miles from the Canadian border, we would not find logs thick enough to provide adequate insulation against the harsh climate. And building another internal insulated frame inside the log walls seemed to defeat the purpose of minimizing the use of materials.
About this time, we stumbled upon the April 1974 issue of National Geographic, which contained a picture of a cordwood home in Skowhegan, Washington. Immediately, we knew that we had found a method of building that satisfied our criteria. Building with cordwood masonry would be cheaper and more efficient than building with conventional methods, as we could salvage “unsuitable wood” to use for construction and we could build the home ourselves. Cordwood’s thick, stalwart walls also would buffer this region's temperature extremes. However, it was probably the unique beauty of these buildings that sealed the deal for us.
Over the past quarter century, Jaki and I have built four homes and innumerable outbuildings with cordwood masonry. In November 2002, we completed a beautiful new sunroom addition to Earthwood, our primary home and the home of Earthwood Building School, where we give workshops on cordwood construction. When people ask us why we're so enthusiastic about cordwood masonry, I am fond of listing what I call the “5-E Advantages.”
- Ease of construction. To lay up a cordwood wall, the builder need never handle anything heavier than a firewood log. Mortar is easily mixed in a wheelbarrow. We have found that the novice owner-builder readily learns the skills. For years, I have been saying that children, grandmothers and beavers can all build cordwood homes...and they do!
- Economy. Log-ends can be cut from less-than-perfect or salvaged wood — fire-killed standing wood, ends and pieces from the sawmill, logging slash, and curved branches and trunks unsuitable for lumber. Even old fence rails and driftwood have been used.
- Energy advantages. Cordwood combines insulation with thermal mass better than any other aboveground building system I can call to mind. The secret is the unique insulated mortar matrix that is woven around all of the log-ends. The mortar does not conduct heat directly through the wall because of an insulated cavity built into the middle third of the wall’s width. With a 16-inch-thick wall, for example, we use a 6-inch-wide insulated space between the inner and outer mortar joints. The insulation can be sawdust and lime (at a 12-to-1 ratio), which results in about R-3 of insulation value per inch of thickness. Other loose-fill insulation, such as perlite or vermiculite, also can be used. (Cellulose, which can trap moisture, is not recommended, and we no longer use fiberglass because of its high energy consumption during manufacture, as well as the danger of inhaling the glass fibers.) Unlike lightweight, wood-frame walls, cordwood walls contain tremendous thermal mass in the mortar. The log-ends themselves also possess both insulative and thermal mass characteristics. Because of this, cordwood homes do not suffer from wild temperature fluctuations; they are easy to keep warm and stay comfortably cool in the summer.
- Environmental harmony. Cordwood masonry makes use of natural, indigenous materials — and even “waste” destined for the landfill. To further mitigate the environmental impacts of construction, some cordwood builders concerned with concrete mortar’s high embodied energy use a cob mortar (clay, sand and straw) instead. My most-recent cordwood construction book, Cordwood Building: The State of the Art (on Mother’s Bookshelf), discusses this innovative technique.
- Esthetics. This acceptable spelling allows me to complete the “5-E” advantages of cordwood. To me, esthetics is just as important as any other consideration, because, ultimately, we must feel good about the house we call home. Jaki and I never tire of the appearance of our walls, which combine the warm colors of wood with the pleasing relief and texture of fine stone masonry. Cordwood offers an almost limitless outlet for creative expression. We like to incorporate special features into the walls, such as shelves and storage nooks. Colorful bottles embedded in the walls admit sunlight in all colors of the spectrum. Our sunroom addition features an Easter Island motif on one of the cordwood panels.
Cordwood accommodates three structural styles quite easily.
Round or curved-wall buildings. A round house makes good use of a quirk of geometry, enclosing a desired space with the least amount of materials. Birds, bees and beavers — as well as so-called “primitive” societies — know this instinctively.
Our round Earthwood house is a good example of using cordwood masonry as a load-bearing structure. The lower courses at Earthwood support two full stories of cordwood masonry plus an extremely heavy earthen roof — sometimes covered with 3 feet or more of snow — a testament to the cordwood’s impressive compressive strength.
Stackwall corners. For a rectilinear house without a heavy post-and-beam frame, stackwall corners can be built of special squared log-ends called quoins. This system enables builders to make walls 24 inches thick or more. The downside to using this method is that, like the load-bearing curved-wall construction, all the cordwood work must be done under the open sky, putting the builder at the mercy of the weather’s whims.
Cordwood infill with a post-and-beam frame. Although I am partial to the circular design, building a strong post-and-beam frame from heavy, rough-cut timbers and putting the roof on prior to commencing the cordwood work offers compelling advantages. Not only does it afford protection from the elements, as you can work on the cordwood infill with a roof overhead, but it also may more easily gain the approval of your local building inspector, as he or she may not be convinced of cordwood masonry’s suitability as a load-bearing medium. For building in seismic (earthquake-prone) areas, the post-and-beam style is the only method of cordwood building I would advise.
Several builders I know have managed to combine the round style with the post-and-beam method by building a 16-sided post-and-beam frame and using cordwood infill. From the outside, such houses look round; inside, they have almost the same advantages of space-enclosing geometry as the truly round house does.
To Learn More
If you’re interested in learning more about cordwood masonry, additional books and Web sites on the subject are available. Along with my books and Web site, www.cordwoodmasonry.com, another helpful site is www.daycreek.com, which lists other resources, tips and tricks helpful to a neophyte builder.
In addition to writing books and articles about cordwood masonry, Rob Roy also is the director of Earthwood Building School in West Chazy, New York, (518) 493-7744. He and his wife, Jaki, have taught cordwood masonry construction across North America, and in Chile and New Zealand.
Cordwood Confusion? Ask the Experts!
Practiced throughout the ages, cordwood masonry construction is experiencing a renaissance as hands-on home builders learn of its simplicity, energy efficiency and unique beauty. But with any unconventional building technique, cordwood construction comes with its own set of challenges. Here, we’ve addressed the most frequently asked questions.
Won't the log-ends rot? If basic care is taken, log-ends will not rot. Fungi, which need constant moisture to thrive, cause wood to rot. Cordwood breathes wonderfully along its end-grain, foiling fungi’s propagation. To ensure long-lived log-ends: 1) Debark the wood; 2) Don’t place wood against wood (this can trap moisture); 3) Don’t use wood that already shows signs of deterioration; 4) Design your roof with at least a 12- to 16-inch overhang; and 5) Set your bottom course of cordwood at least 6 inches off the ground, on a good masonry foundation of stone, block or concrete.
What kind of wood should I use? Select light and airy woods like white cedar, white pine, cottonwood, poplar, spruce or larch (tamarack). These shrink (and expand) less than dense woods such as maple, oak, elm, beech and some of the heavy Southern pines. Denser woods can be used only if special building-design strategies are used.
How long should I dry the wood? Light, airy woods should be dried at least a year, if you can wait that long. This will greatly minimize shrinkage. Dry dense wood just a few weeks, as there is the very real danger of wood expansion with dry hardwoods that get wet from driving rain. Wood expansion is a more serious problem than shrinkage; expansion can break up the wall, whereas wood shrinkage can be attended to in several ways. Research the chosen wood’s shrinkage characteristics before deciding upon a drying time.
What mortar mix should be used? For more than 20 years, we have had good success with a mix of 9 sand, 3 sawdust, 3 lime and 2 Portland cement (equal parts by volume). Use sawdust from a light softwood rather than from a dense hardwood. First, pass the sawdust through a half-inch screen. Then, overnight, completely saturate it by placing it in a soaking vessel such as an old bathtub or an open-topped metal drum. The purpose of the sawdust is to slow mortar-curing time, which reduces mortar shrinkage. If softwood sawdust is not available, use a commercially available cement retarder. Also, use hydrated or Type-S lime, also called builder’s lime, which makes the mix more plastic, and, as the lime calcifies, makes the mortar stronger over time. The Portland cement (either Type I or Type II) lends strength to the mix.
Excerpted from Modern Timber Framing by Rob Roy, Mother Earth News August/September 2004
Many natural building methods — such as straw bale, cordwood masonry and cob building — benefit from timber-frame construction primarily because these methods can involve infilling between the timbers that make up the building's structural framework. Unlike conventional 2-by-4 stick framing, the center-to-center spacing of timber-frame posts is somewhere between 6 and 10 feet. This makes infilling much less tedious; imagine trying to fill the narrow spaces in regular stick construction with cordwood masonry or straw bales.
Also, there is a great practical advantage in erecting a timber frame first — getting the roof on as a protective umbrella, and then infilling the structure using one or more of these natural building methods.
Yes, you can accomplish all this with “traditional” wood-on-wood — such as mortise-and-tenon and dovetail — joining methods. But these methods require intricate cuts and exact measurements, and to do it right, a great deal of time and study must be expended, and there are a few specialized tools that need to be purchased. The reality is that most farmers, contractors and owner-builders use methods of timber framing (also called post-and-beam) that they have simply picked up from colleagues, relatives or neighbors. With the advent of relatively inexpensive mechanical fasteners, most builders — contractors and owner-builders alike — rely on other methods of joining, using truss plates, screws and bolts, pole-barn nails and even gravity.
Timber Framing Advantages
Whether you go with traditional timber framing or (modern) “timber framing for the rest of us,” you will discover certain advantages and disadvantages in both systems.
- Strength. Timber framing by either method is strong in real structural terms. Heavy-timber frames, with or without infilling, are more resistant to trauma from earthquakes, wind uplift and heavy snow load than light-frame construction.
- Conducive to infilling. Heavy-timber framing is more appropriate than stick framing for infilling with natural building techniques. With infilling, it is not critical that exact spacing be left between vertical studs or posts; masonry and cob can fit any space, and straw bales can be made to fit almost any width of space.
- Esthetic appeal. With many of the contemporary timber-frame houses, structural insulated panels (SIPS) are fastened to the outside of the frame, and the beautiful heavy timbers are exposed on the interior. On some cordwood homes, the heavy timbers are in evidence on the exterior, but not on the interior. In all cases, the exposed timbers lend character, texture and an esthetic sense of strength. All of this translates into comfort — spiritual and otherwise.
- Ease of construction. If you’ve never before built a timber-frame structure, you might find it easier than conventional studding.